A railroad frog is a device which is installed at the intersection of two running rails to permit the flanges of railroad car wheels moving along one of the rails to pass across the other rail. The frog supports the car wheels as they pass over the missing rail tread surface between the throat and the point of the frog, and also provides flangeways for the flanges of those car wheels which pass through the frog.
As described in the specification of U.S. Pat. No. 4,624,428, issued in the name of Frank and assigned to the assignee of this application, a standard railroad spring frog includes a rigid wing rail, which is substantially aligned with a long point or heel rail connected to a turnout traffic rail, and a relatively movable wing rail which is substantially aligned with a short point or heel rail that is connected to a main line traffic rail. The movable wing rail is mounted with a yieldable free end, is often spring-biased against the frog long point rail by additional spring means, and provides a substantially continuous support for the wheels of a rail car passing along the main line track. The movable wing rail, sometimes called a spring wing rail, is moved laterally away from the long point rail to provide a wheel flangeway between the long point rail and the spring wing rail when a car wheel flange traversing the long point or rigid wing rail engages the spring wing rail free end and forces or causes it to move laterally to a full open position.
Heretofore, such standard railroad trackwork frogs have utilized conventional horn/horn-holddown assemblies to limit spring wing rail vertical movement when the rail is moved sideways by action of passing car wheel flanges. Such conventional assemblies utilize: (1) sliding-type horn elements that are connected to and project laterally from the spring wing rail, and (2) horn holddown elements that are fastened to a frog base plate, that house riser block elements, and that slidably co-operate with and vertically restrain the sliding-type horn elements. However, it has long been observed that the conventional horn/horn-holddown assemblies are susceptible to excessive abrasive wear at the upper surfaces of the riser block elements and at the upper surfaces of the slide horn elements due to the inherent longitudinal twisting action of the spring wing rail which results as it is moved by flange-originated forces applied laterally to the upper portion of the rail. Also, spring wing rail lateral displacements and longitudinal twisting actions repeatedly effected as a result of wheel-flange forces result in excessive abrasion of the frog base plate element by the lower portion of the spring wing rail at its point of roll-over.
I have invented a new and useful railroad trackwork frog construction, including a new and useful spring wing rail attached roller outrigger subassembly with a co-operating ramp-like roller support, that overcomes the noted deficiencies associated with the prior art railroad trackwork frog conventional construction using slide-type horn/horn-holddown assemblies to effect limited spring wing rail vertical movement. Other objects and advantages of the present discovery will become apparent during a careful consideration of the invention summary, description of the drawings, and detailed description which follow.